Air-controlled-piston door-check



F. P. ANGELL.

AIR CONTROLLED PISTON DOOR CHECK. APPLICATION FILED MAY], 1920.

1,359,144.. Patented Nov. 16, 1920.

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APPLICATION FILED MAY 1, I920.

Patented Nov. 16, 1920.

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j ww' Witnesses m. M W

UNITED. STATES PATENT OFFICE.

FRED r. ANGELL, orBATrLn CREEK, MICHIGAN.

AIR-CONTROLLED-PISTON noon-CHECK.

trolled-Piston Door-Checks, of which thefollowing is a specification.

This invention relates to improvements in air controlled piston doorchecks.

he objectsof the invention are,

First, to provide an effective cylinder and piston structure.

Second, to provide an improved gear structure which shall be variable inits action to secure the desired result.

Further objects and objects relating to details and economies ofoperation and "con-,

struction will definitely appear from the detailed description tofollow.

I accomplish the objects of my invention by the devices and meansdescribed in the followin specifications. The invention is clearlydefined and pointed'out in the claims.

Structures which are preferred embodiments of my invention are clearlyillustrated in the accompanying drawings, forming part of thisspecification, in which:

Figure I is a perspective view of'my improved door check in position ona door with the door closed.

Fig. II is a similar perspective with the door open.

Fig. III is a detail view, somewhat en larged, with parts broken away.

Fig. IV is an enlarged detail sectional view through the piston, rack,gear and guide means for the rack, taken on line 4% of Figs III and V,showing the Valve closed.

Fig. IV is a detail view showing the valve open.

Fig. V is a detail sectional View on line 55 of FigpIV.

Fig. V I is a detail sectional view on line 6-6 of Fig. VIII, showingthe arrangement of the expansion spring within the cup packing.

Fig. VII is a detail sectional view on line 77 of Figs. I and IIIshowing details of the control valve.

Fig. VIII is a detail sectional view simi lar to Fig. IV, showing amodification of the piston and valve.

In the drawings the sectional views are taken looking in the directionof the little Specification of Letters Patent.

Patented Nov. 16, 1920.

Application filed May 1 1920. Serial. No. 378,101.

arrows at the ends of the section lines, and similar numerals ofreference refer to simila'r parts throughout the several views.

'Feferr'ing to the numbered parts of the drawing, 1 is the cylinder ofmy improved door check, provided with a rear head 2 and a head 3containing the gearing connections. These are secured to "the door bysuitable clip pieces 4, I, seen in Figs. I, II and III. Arm 5 isconnected to the actuating part and is connected by link 6 to aclip 7 onthe door casing above the door. Such arm and link connections beingcommon expedients with door checks, theyare not detailed here.

The arm 5 iscarried by the vertical rock shaft 8, which carries upon itthe cam'shaped gear '9, which is geared to actuate the divided head 10,10. The head 10 is provided withafhollow stem-or rod 11 disposed withinthe reciprocating member or rack bar 12, which is provided with lackteeth 13 corresponding to the cam shaped gear 9. The rack bar 12 isguided by engagement with the reduced portion of the head 3.

The piston head 10 is provided with a leather cup-shaped packing 14:,which is re tained in. place by a Washer-15, as seen in Figs. IV andVIII. The cup-shaped packing is expanded and forced again'stthe walls of'the cylinder by the expansion sprin of the cylinder 1.

v The stem 11 is open at 17 through into the cylinder and fits against asuitable gasket 18, and an inlet opening 19 is provided in bar 12 todeliver air through the same.

The head 4 of the cylinder is perforated at 20 with a small aperture,the size of which is regulated by the pointed screw 21 (see Fig. VII),from the cylinder can be very nicely regulated by merely adjusting thescrew 21.

In Fig. VIII, I show a modification of the piston construction. Thisconsists of a head 22 carried by a yoke 23 on the rack bar 12. Thepiston is perforated at 24 and provided with a surrounding valve seat25, and a sole leather valve 26 is provided to seat against this valveseat. The valve is drawn securely to place by the coil spring 27 securedthereto and attached to the eye 28 within the yoke 23.

The piston in .either structure is urged toward its head by means of thespring 29.

so that the escape of the air With my improved door check in place whenthe door is open the arm 5 is swung, and through its connection to therock shaft 8 acts upon the cam shaped gear .9, which moves the irregularrack bar 12 carrying the piston from the bottom of the cylinder and airenters through the valved opening in the piston.

When the door is released and allowed to close, the spring 29 reactsupon the piston and closes the air opening, confining the air within thecylinder and compressing the same, as shown. This swings the door shutat a rapid rate, becausethe spring acts on the short radius of the gear.The door will be checked before it closes because of the resistance ofthe air compressed within the cylinder. The spring, however, tends tofurther close the door, and the air gradually escapes through therestricted aperture 20. When the air escapes, because the rack is actingon the gears of the longer radius, it very readily and easily closes thedoor by a slow moving strong pressure. r

The structure I have shown in Fig. IV is very positive in its action andhighly efiective, but the structure illustrated in Fig.

I VIII is also effective and much more economical to produce.

It is of the highest consequence to completely confine the air so as toinsure its resistance until released through the regulated aperture.Having thus descrlbed my inventlon, what I claim as new and deslre tosecure by Letters Patent, is

ing, an expansion spring ring within the cupped packing to close thesame into close contact with the cylinder walls, a cam shaped piniondisposed in the opposite end of said cylinder, on an axis transverse tothe cylinder an irregular rack bar meshing with said pinion and guidedon the head and connected to the said. piston, a spring within thecylinder arranged to urge the piston into the said cylinder, a valvedopening through the said piston head comprising a stem on thesaid'piston entering a recess in said rack bar, witha valved opening atthe end thereof, stop means to limit the opening of the Isiaicil valve,coacting for .the purpose specie r r V 2. In a door check thecombination of a suitable cylinder, with a restricted regulateddischarge opening at the head thereof, a pis-.

ton therein with a cupped leather packing, an expansion spring ringwithin the cupped packing to close the same into close contact with thecylinder walls, a cam shaped pinion disposed in the opposite end of saidcylder, on an axis transverse to the cylinder an irregular rack barmeshing with said pinion and guided on the head and connected to thesaid piston, a spring within the cylinder arranged to urge the pistoninto the said cylinder, and a valved opening in the piston head to admitair as the piston is withdrawn, coacting for the purpose specified.

In witness whereof I have hereunto set my hand and seal in the presenceof two witnesses.

FRED P. ANGELL. [1,. s]

Witnesses MYRA L. SKELLENGER, L, H. SABIN.

